A Cyclisation and Docking Protocol for Cyclic Peptide-Protein Modelling using HADDOCK2.4

An emerging class of therapeutic molecules are cyclic peptides with over 40 cyclic peptide drugs currently in clinical use. Their mode of action is, however, not fully understood, impeding rational drug design. Computational techniques could positively impact their design but modeling them and their interactions remains challenging due to their cyclic nature and their flexibility. This study presents a step-by-step protocol for generating cyclic peptide conformations and docking them to their protein target using HADDOCK2.4. A dataset of 30 cyclic peptide-protein complexes was used to optimize both cyclisation and docking protocols. It supports peptides cyclized via an N- and C-terminus peptide bond and/or a disulfide bond. An ensemble of cyclic peptide conformations is then used in HADDOCK to dock them onto their target protein using knowledge of the binding site on the protein side to drive the modeling. The presented protocol predicts at least one acceptable model according to CAPRI criteria (Critical Assessment of Prediction of Interaction) for each complex of the dataset when the top 10 HADDOCK-ranked single structures are considered (100% success rate top10) both in the bound and unbound docking scenario. Moreover, its performance in both bound and fully unbound docking, is similar to the state-of-the-art software in the field, Autodock CrankPep. The presented cyclisation and docking protocol should make HADDOCK a valuable tool for rational cyclic peptide-based drug design and high-throughput screening.